A new, special issue of Smithsonian magazine attempts the impossible: to list out the most significant people in United States history

How much does Thomas Paine matter? More than Harriet Beecher Stowe? Less than Elvis? On a par with Dwight Eisenhower? Would you have answered these questions differently ten years ago? Will you answer them differently ten years from now? In a culture so saturated with information and so fragmented by the search possibilities of the Internet, how do we measure historical significance?

Steven Skiena and Charles B. Ward have come up with a novel answer. Skiena is the Distinguished Teaching Professor of Computer Science at Stony Brook University and a co-founder of the social-analytics company General Sentiment. Ward is an engineer at Google, specializing in ranking methodologies. Their answer involves high-level math. They subject the historical zeitgeist to the brute rigors of quantitative analysis in a recent book, Who’s Bigger? Where Historical Figures Really Rank.

In this fascinating book, Steve Skiena and Charles Ward bring quantitative analysis to bear on ranking and comparing historical reputations. They evaluate each person by aggregating the traces of millions of opinions, just as Google ranks webpages.

Simply put, Skiena and Ward have developed an algorithmic method of ranking historical figures, just as Google ranks web pages. But while Google ranks web pages according to relevance to your search terms, Skiena and Ward rank people according to their historical significance, which they define as “the result of social and cultural forces acting on the mass of an individual’s achievement.” Their rankings account not only for what individuals have done, but also for how well others remember and value them for it.

Their method requires a massive amount of big data on historical reputation. This they found in the English-language Wikipedia, which has more than 840,000 pages devoted to individuals from all times and places, plus data extracted from the 15 million books Google has scanned. They analyzed this data to produce a single score for each person, using a formula that incorporates the number of links to each page, the number of page visits, the length of each entry and the frequency of edits to each page. Their algorithms differentiate between two kinds of historical reputation, what they call “gravitas” and “celebrity.” Finally, their method requires a means of correcting for the “decay” in historical reputation that comes with the passage of time; they developed an algorithm for that, too. By their reckoning, Jesus, Napoleon, Muhammad, William Shakespeare and Abraham Lincoln rank as the top five figures in world history. Their book ranks more than 1,000 individuals from all around the world, providing a new way to look at history.

Skiena and Ward would be the first to acknowledge that their method has limitations. Their concept of significance has less to do with achievement than with an individual’s strength as an Internet meme—how vividly he or she remains in our collective memory. The English-language Wikipedia favors Americans over foreigners, men over women, white people over others and English speakers over everyone else. In their rankings of Americans only, past presidents occupy 39 of the first 100 spots, suggesting an ex-officio bias.

That’s where we come in. Smithsonian magazine has been covering American history in depth from its inaugural issue, published in 1970. Among the Smithsonian Institution museums we work closely with is the National Museum of American History. By synthesizing our expertise with the systematic rigor of Skiena and Ward’s rankings, we sought to combine the best of quantitative measures and qualitative judgment.

First, we asked Skiena and Ward to separate figures significant to American history from the world population. Then, rather than simply taking their top 100, we developed categories that we believe are significant, and populated our categories with people in Skiena and Ward’s order (even if they ranked below 100). This system helped mitigate the biases of Wikipedia.

We have highlighted what we decided was the most interesting choice within each category with a slightly fuller biographical sketch. And finally, we made an Editors’ Choice in each category, an 11th American whose significance we’re willing to argue for.

Argument, of course, has been integral to American historiography from the beginning. When Andrew Gelman, a professor of statistics and political science at Columbia University, wrote that Who’s Bigger? “is a guaranteed argument-starter,” he meant it as a compliment. We hope our list will spark a few passionate discussions as well.